


That Dark Mirror on the Wall

by octopus_fool



Category: Harry Potter - J. K. Rowling
Genre: F/F, Incest, Sibling Incest, dubcon, mention of harm to animals
Language: English
Status: Completed
Published: 2017-02-08
Updated: 2017-02-08
Packaged: 2018-09-22 20:30:08
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,030
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9624185
Author URL: https://archiveofourown.org/users/octopus_fool/pseuds/octopus_fool
Summary: Andromeda feels estranged from her sister and is surprised by a night time visit.





	

**Author's Note:**

  * For [afinch](https://archiveofourown.org/users/afinch/gifts).



Andromeda returned from the edge of sleep as her bed dipped beneath the weight of an additional person. She blinked, seeing the outline of her sister’s curls against the moonlit window.

“Bellatrix?”

“The very same.”

“What are you doing here?” 

“I wanted to see my favourite sister.” Bellatrix’s teeth shone in the darkness as she smiled.

Andromeda wondered just how she could be Bella’s favourite sister when they had barely seen each other all school year. She often saw the Greengrass sisters whispering together in a corner and envied their closeness, even though three years in age separated them in contrast to the one year that lay between her and Bellatrix. 

“Don’t let Cissy hear that,” she replied, letting a smile creep into the words.

“Oh, don’t worry about Cissy,” Bellatrix replied. “She’d be happy enough again once you give her a few compliments and maybe a present.”

She was probably right about that, Andromeda thought. Their little sister was not one to bear a grudge, not when she could wrap people around her finger instead. Their mother sometimes worried about her naivety.

“Still,” Andromeda retorted. “And it wouldn’t be nice.”

“Ever the perfect one, aren’t you, Andromeda?” Bellatrix ribbed. “But I’m not really here to debate favourites. I just missed you and thought we could talk like in old times.”

Andromeda laughed. “When we were young and not old hags with creaking backs and warts on our noses?”

“I’ll have you know I don’t have warts, and certainly not on my nose,” Bellatrix teased back. “And I’m not _creaky_.”

“You’re not?” Andromeda asked and gave her sister a playful shove.

Bellatrix shoved back, only to tumble fully onto the bed. She grabbed a pillow and threw it at Andromeda, who retaliated. Before long, they were in a full-blown pillow fight, flinging pillows at each other until they collapsed next to each other in laughing exhaustion. 

“I missed that,” Bellatrix said, her eyes resting on Andromeda’s face. 

“I did too,” Andromeda replied. Something in Bellatrix’s stare was making her uneasy.

Bellatrix leaned forward and kissed her.

To Andromeda’s surprise, her sister was an excellent kisser. Just the right amount of pressure, some tongue and her lips were incredibly soft. But above all, she was her _sister_. Andromeda felt panic rising and pushed Bellatrix away.

“Bellatrix, what...”

“Shh, I was just wondering about something. Have you ever heard of Narcissus?”

“Of course I have. Our sister is named after him, for Merlin’s sake.”

“Well, yes. I’ve always thought that story was a load of rubbish. What good is water?” Bellatrix paused for a moment. “Have you ever kissed a mirror?”

“They are cold, flat and guaranteed to be unsatisfying,” Andromeda said drily.

“Exactly. But...”

“I am not your bloody mirror, and you know that! We are not that alike and you know how much I hate when people confuse us for...”

Bellatrix’s lips were on hers again. There was that same flash of panic. They should not be doing this, it was wrong, so wrong. But at the same time, rage filled Andromeda. She had never liked being silenced and certainly not in the middle of an argument. 

Andromeda could see that Bellatrix hadn’t closed her eyes, was watching her for a reaction, waiting for her to pull away. Bellatrix sucked on her lower lip and Andromeda followed suit, seeing Bellatrix’s eyes widen in surprise. 

Andromeda bit down. She bit down harder than she had thought and tasted a metallic tang. 

“Oww!” Bellatrix’s mouth was still against hers and she could feel the breath of the exclamation against her. A strange sense of exhilaration ran down Andromeda’s spine and she felt a giggle escape her lips.

Bellatrix stared at her. “You wait...”

Bellatrix closed the minute gap between them, kissing Andromeda even more fiercely than before. She bit on Andromeda’s lip, stopping just short of pain. 

Andromeda was not sure what made her do it. Perhaps she didn’t want to show weakness. Maybe the remaining rage pushed her on. Either way, she kissed back.

If Bellatrix was surprised, she did not show it and before long, Andromeda was struggling to give as good as she received. There was no way she would let Bellatrix gain the upper hand. 

Andromeda felt Bellatrix’s lips curl into a smile beneath her mouth.

The hand that had been resting on Andromeda’s thigh slowly slid upwards and slipped into her panty. Andromeda froze.

“Do you want me to stop, Andy?” Bellatrix’s voice was sweet and caring, down to the childhood nickname.

It was a dare, it was always a dare with Bellatrix. It had been when they had eaten those strange sweets at their cousins’ house that left them in St. Mungos for a week, it had been a dare when they had dunked Sirius under water and it was a dare now. Andromeda could almost hear Bellatrix’s sing-song voice, teasing her of being afraid.

“No. Don’t stop.”

Andromeda ran her own hand up Bellatrix’s thigh. Bellatrix grinned at her, that grin that always meant that nothing good would follow. 

“Don’t worry, I won’t hurt you.”

She didn’t. Her nails on Andromeda’s back, her mouth sucking on her skin, her hand tugging at her hair, and Bellatrix didn’t hurt her once. She wasn’t gentle, Andromeda always expected pain at any moment, though she took care not to show it. Bellatrix played with the edge of pain, knew just where to stop, where things would become too painful. 

Andromeda couldn’t help but wonder how she knew so well. Unbidden, an image from her childhood rose before her eyes. Bellatrix holding a small bird that had crashed into one of the large windows of their house. One of the wings was at an odd angle and the bird shrieked in pain as Bellatrix prodded at the wing, her eyes wide in curiosity.

A sharp tug at her hair made Andromeda gasp and Bellatrix shuddered to a climax around her fingers. Her shuddering gasps had Andromeda following her over the brink.

As she sank back against the mess of cushions, Andromeda’s face burned with shame. Perhaps she would be able to forget this had ever happened when morning came.


End file.
